| Titre | Biotite chemistry as a monitor of magma fertility and mineralisation potential: results from the Devonian granitoids of New Brunswick |
| Télécharger | Téléchargements |
| |
| Licence | Veuillez noter que la Licence du gouvernement
ouvert - Canada remplace toutes les licences antérieures. |
| Auteur | Azadbakht, Z ;
Lentz, D R; McFarlane, C R M; Rogers, N |
| Source | TGI 4 - Intrusion Related Mineralisation Project: new vectors to buried porphyry-style mineralisation; par Rogers, N (éd.); Commission géologique du Canada, Dossier public 7843, 2015 p. 563-564, https://doi.org/10.4095/296492  Accès ouvert |
| Liens | Canadian Database of Geochemical Surveys, downloadable files
|
| Liens | Banque de données de levés géochimiques du Canada,
fichiers téléchargeables
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| Image |  |
| Année | 2015 |
| Éditeur | Ressources naturelles Canada |
| Document | dossier public |
| Lang. | anglais |
| DOI | https://doi.org/10.4095/296492 |
| Media | en ligne; numérique |
| Référence reliée | Cette publication est contenue dans TGI 4 -
Intrusion Related Mineralisation Project: new vectors to buried porphyry-style mineralisation |
| Référence reliée | Cette publication est reliée à les
publications suivantes |
| Formats | pdf |
| Province | Nouveau-Brunswick |
| SNRC | 21G; 21H; 21I; 21J; 21O; 21P |
| Lat/Long OENS | -68.0000 -64.0000 48.0000 45.0000 |
| Sujets | gisements porphyriques; cuivre porphyrique; prospection minière; minéralisation; biotite; tungstène; étain; molybdène; or; antimoine; roches magmatiques; roches intrusives; roches ignées; gisements
filoniens; magmatisme; differentiation magmatique; gîtes magmatiques; géologie économique; pétrologie ignée et métamorphique; géochimie; Paléozoïque; Dévonien |
| Illustrations | cartes de localisation; graphiques; photomicrographies |
| Programme | Initiative géoscientifique ciblée (IGC-4) Étude des gîtes porphyriques |
| Diffusé | 2015 06 11; 2023 03 17 |
| Résumé | (disponible en anglais seulement)
There are over 150 granitoid intrusions in the New Brunswick; however, all the mineralised intrusions formed in relation to Acadian and Neoacadian orogenic
phases of Appalachian accretion. These granitoids range in age from 423 to 360 Ma, and include examples of pre-, syn-, late-, and post-tectonic emplacement with affinities ranging from primitive to highly evolved A-, S-, and I-types granitoids along
with their hybrid varieties. Many of these are spatially and temporally related to specific styles of mineralization, producing deposits of Sn, Ta, Li, Sb, W, Mo, Cu, and Au, as well as other base-metals and U.
Igneous biotite crystallises over a
wide range of conditions and reacts very sensitively to physio-chemical conditions like halogen and oxygen fugacities, pressure, temperature and chemical composition of the magmas. This sensitivity makes biotite a suitable mineral for identifying the
petrogenetic processes, mineralization and alteration of the host granitic rocks. The following features make biotite a valuable probe of magma composition: i) It is the most important reservoir of any excess aluminium in granites that do not contain
modal garnet, cordierite, or the Al2SiO5 polymorphs; therefore, it directly reflects the peraluminosity of the host magma in such rocks; ii) it is the most readily available indicator of oxidation state; and iii) it can provide information about the
F and Cl composition of the magma.
Previous studies have shown that biotite, and to lesser extent hornblende and magnetite, continuously equilibrates with host liquids. Consequently, a core-to-rim study of these minerals and their compositional
zoning can provide a record of magma evolution so that the origin and evolution of granitoids can be documented. The aim of this study is to calculate fluoride and chloride activity of aqueous fluids based on measuring F and Cl contents in the
minerals containing hydroxyl and halogens, using a combination of electron microprobe and Laser Ablation ICP-MS. These data will be combined and compared with whole-rock trace element geochemistry. The results are expected to help constrain
crystallisation conditions, volatile exsolution, and fluorine-chlorine activity of fluids associated with these intrusions, and also to examine the degree of subsolidus re-equilibration using various geothermobarometry techniques. By linking these
results to the various styles/types of granitoids and their associated mineralisation it is hoped to establish biotite composition as a robust indicator of an intrusions ore potential. |
| Sommaire | (Résumé en langage clair et simple, non publié)
L'Initiative géoscientifique ciblée (IGC-4) est un programme géoscientifique fédéral de collaboration qui fournit à l'industrie les
connaissances géoscientifiques et les techniques novatrices de prochaine génération dont elle a besoin pour mieux détecter les gîtes minéraux enfouis, réduisant ainsi certains risques liés à l'exploration. Ce volume résume les activités de recherche
effectuées dans le cadre du projet de minéralisation lié à des intrusions de l'Initiative géoscientifique ciblée 4 qui était axé sur des systèmes minéralisés porphyriques associés aux dépôts de Cu et de Cu-Mo dans le centre-sud de la
Colombie-Britannique et aux dépôts de Sn-W-Mo-In au Nouveau-Brunswick, en Nouvelle-Écosse et à Terre-Neuve-et-Labrador. |
| GEOSCAN ID | 296492 |
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